How many watts does the human body use

[Lok]

2000 Kcal is a average human nutitional intake so that is 8368000 J per day divided by the number of seconds in one day that gives a rough 96.85 W.

The amount of lost heat varies during day and nighttime but mostly we give about the same heat as a 100 W light bulb.

 

[bimbim]

are you on facebook?

 

[harborsparrow]

Having had a few severe asthma attacks in the past (resulting in trips to emergency rooms), I found that my need for oxygen increased significantly when required to understand human speech.

For what it's worth, don't talk to you kids anymore than absolutely necessary if they have an asthma attack.

I imagine whether parsing speech or not might change your power calculations significantly.

 

[pbagnall]

Interestingly I saw something on TV a while ago which was talking about why human aren't furry, and it has mostly to do with being able to dump heat from our bodies. They did a simple experiment to see how much heat the body could get rid of by sweating, and it managed well over 1kW. It seems reasonable that if we're capable of dumping that much heat, we're probably able to produce that much by various metabolic processes.

I also went for a run this morning. I log my time on runkeeper.com, which tells you an estimate of how many calories you've burnt (burnt, not the amount of mechanical work you've done). A 30min run of about 4.5km burnt 400kcal, which is about 1.6MJ, which works out at about 860W. Assuming runkeeper is right about the number of calories burnt, that's not a bad power output - mostly in the form of waste heat judging by my state at the end of the run ;-).